Developed a SHA1-based duplicate file upload prevention feature for the OpenListTeam/OpenList repository, focusing on backend optimization and API development using Go. The solution introduced automatic file reuse by comparing SHA1 hashes, allowing the system to skip redundant uploads when a matching file already exists. This approach reduced bandwidth consumption and storage requirements, particularly benefiting large-file workflows by accelerating upload times and lowering operational costs. The work included extending API support in drivers/123open to streamline deduplication across different upload paths, as well as implementing minor code hygiene improvements to enhance maintainability and ensure consistent, reliable backend performance.